[Live-devel] how to make latency as low as possible

[Ross Finlayson]

> Continuing question 1, I see that deliverFrame() is called by two callers, doGetNextFrame(), which is called by sink object, and deliverFrame0(), which is called by event loop when signalNewFrameData() emits an event. In my case, I left signalNewFrameData() never called, hence deliverFrame0() never called.

Yes, that was the wrong thing for you to do - because it means that if “doGetFrame()” happens to get called when no frame is immediately available to be delivered, then “doGetFrame()” will return immediately, but no delivery will ever get done.  (See “DeviceSource.cpp”, line 92.)

You are doing event-driven programming; you need to understand this.  If no frame is immediately able to be delivered, then you should not ‘block’, waiting for a frame to come available.  Instead, you must arrange for an event to get handled when a frame later becomes available.  One common way to do this is to have a separate thread for you encoder; this thread would call no LIVE555 library function *except* “triggerEvent()”.

This is all explained very clearly in our FAQ, and in the comments in “DeviceSource.cpp”.  Therefore - to avoid bothering the hundreds of mailing list subscribers any more - this will be my (and your) last posting on this topic.


Ross Finlayson
Live Networks, Inc.
http://www.live555.com/